Cheap wire selection.

[Lampy]

Hi, i have calculated that due to distances, voltage and voltage drop of something i am making i need some fairly hefty sized wire. 10/12 gauge infact. Sorry about my ignorance in electrical matters, but could i get away with using quality speaker cable for this? 200/300 strand type stuff. This seems like the cheapest option as speaker cable often comes in long lengths at cheap prices. http://www.ebay.co.uk/itm/50m-HiFi-Speaker-Loudspeaker-Cable-Wire-2x-2-5mm-Multi-strand-434-2-x-217-/280888006379?pt=UK_Computing_Sound_Vision_Audio_Cables_Adapters&hash=item41663ad6eb for example. I have attached a picture of my project as a reference. As i know nothing about electrical stuff is it a case that aslong as the cable is over a certain size (diameter) it will deliver the correct voltage and be able to draw enough current for it's use regardless of how much bigger it gets? So for example if 20 gauge is right for the job, will 10 gauge perform exactly the same? Or does going bigger than necessary create other issues? Thanks

 

[AAH]

The attached picture that you mentioned isn't coming up.
The size of that cable is pretty much the same as http://www.altronics.com.au/index.asp?area=item&id=W2130 whose wholesale price is about the same as that ebay price. The 200/300 strand wire tends to be dearer than equivalent sized wire with 20-50 strands.
I have personally used automotive 2 core stuff like http://www.altronics.com.au/index.asp?area=item&id=W4150 but I have no idea what I paid for it and it was at wholesale price from an auto elec outlet.
The bigger the cable size the better. The best option is to keep the cable runs as short as possible but if they can't be made short then thick wires is the only way you'll get acceptable volts to your lights.

 

[Lampy]

Thanks for the input. Drawing now attached. My only real option other than super thick cable is more power supplies. But they are not cheap.

 

[AAH]

You are going to need to provide power injection along the strips as you have a few, they are high current and they are 5V. The obvious thing to do is to link from the power supply to each of the 4 posts (?). The cable then doesn't have to be carrying the full 37A and the voltage along the length will be more uniform.
I still wouldn't go with especially small cable myself. I'd probably be using wire of about 1.2 to 1.5mm2.

 

[elvatrdude]

If you haven't already purchased your strips, you might consider going with 12V 2811 strips. The current will be cut by approx 2/3, requiring wire with a much smaller cross section. Kevin

 

[fasteddy]

You may want to refer to this thread on understanding how current, cable length and cable guage effect voltage drop